Longview Inspection conducted an infrared thermal test on a stock 2003 Harley–Davidson with 3,021 miles and a Twin Cam 88 engine. For each test the motorcycle was started and allowed to idle at 1,000 rpms until temperature levels peaked and stabilized. Look at the pictures below.
Below are three cam chain tensioners from an American V-Twin engine with 10,000 miles of use. The tensioner on the left used the manufacturer’s conventional oil. The tensioner in the middle used the manufacturer’s synthetic oil. The tensioner on the right used Royal Purple after an initial break-in period of 1,500 miles. The difference in wear is dramatic.